Drive means for interval timer

ABSTRACT

A gear is responsive to a cylinder rotating at constant speed through two sets of teeth with one of the sets having a thickness greater than the other. The cylinder includes an actuator engaging the teeth and also a peripheral recess to receive the set of teeth having the greater thickness. When the cylinder is in a position such that the recess is not aligned with one of the teeth having the greater thickness, the cylinder prevents rotation of the gear. A first set of cams is responsive to the intermittent rotation of the gear, while a second cam is responsive to the constant speed rotation of the cylinder.

United States Patent Weber et al.

DRIVE MEANS FOR INTERVAL TIMER Inventors: Richard H. Weber; Maurice E.

Schuder, both of Indianapolis, Ind.

P. R. Mallory & Co. Inc., Indianapolis, Ind.

Filed: Nov. 15, 1971 Appl. No.: 199,071

Related US. Application Data Continuation of Ser. No. 44,003, June 8, I970, abandoned.

Assignee:

U.S. CI. 74/84, 74/3.S2 Int. Cl. Fl6h 27/04 Field of Search 74/3.5, 3.52, 3.54,

References Cited UNITED STATES PATENTS 3/1972 Illman et al 74/112 [451 July 24, 1973 2,881,630 4/1959 Opocensky 74/435 3,077,784 2/1963 Laviana et al. 7413.52

Primary Examiner-Charles J. Myhre Assistant ExaminerF. D. Shoemaker Attorney-Richard H. Childress, Robert F. Meyer et al.

[57] ABSTRACT A gear is responsive to a cylinder rotating at constant speed through two sets of teeth with one of the sets having a thickness greater than the other. The cylinder includes an actuator engaging the teeth and also a peripheral recess to receive the set of teeth having the greater thickness. When the cylinder is in a position such that the recess is not aligned with one of the teeth having the greater thickness, the cylinder prevents rotation of the gear.

A first set of cams is responsive to the intermittent rotation of the gear, while a second cam is responsive to the constant speed rotation of the cylinder.

9 Claims, 4 Drawing Figures PATENTEUJUW'QH 3.747. 420

sum 1 or 2 HUU INVENTORS RICHARD H. WEBER MAURICE E. SCHUDER ATTORNE l Hlllll SHEET 2 [IF 2 INVENTORS RICHARD H. WEBER MAURICE SCHUDER ATTORNEY DRIVE MEANS FOR INTERVAL TIMER termittent drive mechanism serves as a means for coupling the output shaft of a constant speed motor to the control cams of the timer. Its purpose is to provide a periodic rotational motion to the control cams.

As appliances become more complicated, the timing mechanismsrequired to control the appliances also tend to become more complicated. However, as would be expected, as the timing mechanisms become more complicated they become more costly and occupy more space.

For most appliances, it is highly desirable to be able to manually set the desired program sequence. In such cases means need to be provided for such manual adjustment.

Some appliances have become sufficiently complicated that, in addition to the normal sequencing provided by the cam means, some timing mechanisms provide for sub-interval timing means. Such means provide for a shorter time interval than normally provided for by the cam means of the timing mechanism. Where such intervals are required, the intermittent drive mechanism should also provide a means for providing a sub-interval means.

The present invention is concerned with an intermittent drive mechanism. and it has as one of. its objects a provision of such a drive mechanism which is neat, compact, and occupies a minimum of space. 7

Another object of the invention is to provide an intermittent drive means having means for providing .a subinterval timing means.

A further object of the invention is to produce an intermittent rotation in conjunction with a locked gear train. The gear train is free to transmit motion only when the intermittent motion occurs and remains locked during the dwell time of the intermittent motion producing component.

Another object of the invention is to provide an intermittent drive means for driving a cam means which includes cylindrical drive means responsive to movement of constant speed motor drive means and having an actuator means to energize a gear means.

Still another object of the invention is to provide an intermittent drive means which includes a gear means responsive to the movement of the cylindrical drive means, the gear means including two sets of teeth, one of the sets having a thickness greater than the other.

Yet another object of the invention is to provide an intermittent drive means having a cylindrical drive means and a gear means having two sets of teeth with one of the sets having a thickness greater than the other and a recess meant in the periphery of the cylindrical drive means to receive the set of teeth having the greater thickness.

Another object of the invention is to provide an intermittent drive means which permits the timing sequence for an appliance to be readily manually adjustable.

Still another object of the invention is to provide an intermittent drive means which includes a directional ratchet and pawl drive means.

A further object of the invention is to provide an intermittent drive means having a directional ratchet and pawl drive means which includes a ratchet wheel carried by a shaft, and a pivotally mounted pawl caried by a gear mounted on the shaft, the other end of the pawl also mounted on the gear, the pawl having a tooth adapted to engage the ratchet wheel.

Still a further object of the invention is to provide an intermittent drive means having a sub-interval means which includes at least one pivotally mounted levers responsive to a cam means which includes two peripheral tracks of coded indicia separated by a peripheral ridge.

These and other objects of the invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a bottom view of a typical timing mechanism with portions thereof being removed to show the intermittent drive means;

1 FIG. 2 is a view taken along lines 2-2 of FIG. 1;

FIG. 3 is a view taken along lines 3-3 of FIG. 2; and FIG. 4 is a view similar to FIG. 3 showing another mode of operation.

Generally speaking, the objects of the invention are accomplished by providing an intermittent drive means for driving a cam means of a timing mechanism which includes a constant speed motor drive means, a cylindrical drive means coupled to and responsive to movement of the motor drive means, the cylindrical drive means including a peripheral recess, an actuator means disposed on each side of the recess, gear means responsive to movement of the cylindrical drive means, the gear means including two sets of teeth one of the sets having a thickness greater than the other. Rotation of the cylindrical drive means causes engagement of the actuator means with the sets of teeth so as to rotate the gear means as the set of teeth of greater thickness rotates through the recess. Further rotation of the cylindrical drive means engages the set of teeth of greater thickness with the side of the cylindrical drive means so as to hold the gear means from rotation.

Referring now to the drawings, there is shown a timing mechanism 10 only the essential features of which have been shown for a more clear understanding of the intermittent drive means of the invention. In general, the timing mechanism 10 includes an intermittent drive means 12, cam means which is responsive to movement of the intermittent drive means, a constant speed drive means 16, and electrical terminals 18 which are electrically connected to electrical switches (not shown), the switches being responsive to rotation of cam means 14. Also included as part of the intermittent drive means 12 is a sub-interval means 20. The timing mechanism is at least partially enclosed through a bottom plate 1 I, a top cover plate 13 for the cam programming means section of the mechanism, and a cover 15 for the drive portion of the mechanism. Cover plate 13 is held in proper relation to bottom plate 11 through stakes 17. Drive means 16 is of a constant speed. type and could, for example, include a synchronous motor I6. Also included as part of the constant speed drive means is a speed reducing means such as a gear train enclosed in housing 19.

lntermittent drive means 12 includes cylindrical drive means 22, gear means 23, and means 26 coupling the gear means 23 to the cam means 14. Cylindrical drive means 22 has, as shown, a generally cylindrical peripheral surface 28 having a recess 30 formed therein. The cylindrical drive means 22 also includes actuator means 32 which includes posts 32 and 32" disposed at each side of the recess 30. Cylindrical drive means 22 is journalled in bottom plate 11 through hub 34 and in cover through bearing 33 and pilot 35. The cylindrical drive means is rotatably driven by constant speed drive means 16 through motor pinion 38 which meshes with pinion 36.

Gear means 23 includes gears 24 and 40. Gear 24 includes two sets of gear teeth 24' and 24", one set of which (teeth 24") has a greater thickness than the other. More specifically, gear teeth 24" has teeth the thickness of which is the full thickness of the gear, while gear teeth 24' has teeth of half-thickness. Gear means 23 is journalled in bottom plate 11 and cover 15 through hub 42. Gear 40 engages gear 46 of the means 26'coupling the gear means 23 with the cam means 14. Means 26 also includes pinion 48 and directional drive means 44. Gear 46 and pinion 48 are independently rotatably carried by shaft 50. Pinion 48 meshes with gear 52 which is carried by rotating shaft 54 which also carries cam means 14. The gear 46 is coupled to pinion 48 through directional drive means 44. Directional drive means 44 includes pawl 43 pivotally carried on gear 46 through post 47, and ratchet wheel 45 which is constructed unitarily with pinion 48. Pawl 43 is resilient with its free end sprung about post 49.

The operation of the intermittent drive means can now be described with reference to the elements thus far illustrated. Synchronous motor 16' turns pinion 38 at a constant speed in a predetermined direction. Pinion 38 will drive cylindrical drive means 22 through pinion 36. Assuming cylindrical drive means 22 can be rotated in a counterclockwise direction, as the actuator means 32 approaches the teeth of gear 24, (FIG. 3), post 32" will engage one of the teeth 24' of less than full thickness, while one of the teeth 24" of greater thickness engages recess 30 as it is driven by post 32'. When, as shown in FIG; 4, recess 30 passes the interference path of the gear means 24 the full teeth 24" engages the side 28 of the cylindrical drive means 22 thus preventing further rotation of the gear means 24. Thus, the intermittent drive means will only advance the cam means 14 when the actuator means 32 of the cylindrical drive means comes into engagement with the gear means 24. The intermittent rotation of the gear 24 causes intermittent rotation of gear 40 which in turn causes rotation of gear 46. Rotation of gear 46 causes rotation of ratchet wheel 45 through the engagement of tooth 43' with the ratchet wheel. Rotation of ratchet wheel 45 causes rotation of pinion 48 which in turn causes rotation of gear 52 thus causing intermittent rotation of cam means 14.

The use of the directional drive means 44 in combination with the holding feature of the cylindrical drive means permits the cam means 14 to be manually set without driving through" the motor 16. Specifically because of the holding feature of the cylindrical drive means the tooth 43' of pawl 43 will disengage from ratchet wheel 45 when the cam means 14 is rotated in the proper direction (clockwise).

The intermittent drive means also includes subinterval means 20. Sub-interval means 20 includes a pair of levers 62 and 64 pivotally carried on post 66, and cam means 68. As shown in FIG. 2, cam means 68 is unitarily constructed with cylindrical drive means 22 and includes two tracks 68' and 68" of coded indicia separated by a peripheral ridge 70.

As the cam follower 72 of each lever rides over the coded indicia the levers pivot to actuate sub-interval electrical switches (not shown). The use of the subinterval allows for shorter time sequences than are available from cam means 14.

Thus there is described an intermittent drive means which is neat and compact, enables the time sequencing of an appliance to be manually changed without manually driving through the motor drive and which provides a means for ready use of sub-intervals.

What is claimed is:

1. An intermittent drive means for driving a cam means comprising:

a. a constant speed motor drive means,

b. cylindrical drive means coupled to and responsive to movement of said motor drive means, said cylindrical drive means including a peripheral recess, and actuator means disposed on each side of said recess,

c. gear means responsive to movement of said cylindrical drive means, said gear means including two sets of teeth, one of said sets having a thickness greater than the other,

d. rotation of said cylindrical drive means causing engagement of said actuator means with said sets of teeth so as to rotate said gear means as the set of teeth of greater thickness rotates through said recess, further rotation of said cylindrical drive means engaging said set of teeth of greater thickness with the side of said cylindrical drive means so as to hold said gear means from rotation,

e. means coupling said gear means to said cam means, including a ratchet wheel carried by a shaft, and a substantially semi-circular pawl carried by a gear mounted on said shaft and a tooth extending from said semi-circular pawl.

2. An intermittent drive means according to claim 1 wherein said actuator means includes a post disposed at each side of said recess.

3. An intermittent drive means according to claim 1 further including sub-interval means responsive to rotation of said constant speed motor drive means.

4. An intermittent drive means according to claim 3 wherein said sub-interval means includes: a cam means coupled to said constant speed motor drive means and at least one pivotally mounted lever means responsive to said cam means.

5. An intermittent drive means according to claim 4 wherein said sub-interval cam means includes two peripheral tracks of coded indicia separated by a peripheral ridge.

6. An intermittent drive means according to claim 5 wherein there are a pair of said pivotally mounted lever means.

7. In an intermittent drive means wherein gear means and ratchet means are used to intermittently advance a cam means, the improvement comprising a ratchet wheel carried by a shaft; a semi-circular resilient pawl pivotally carried at one end by a gear mounted on said shaft, the other end engaging a post carried by said gear; and a tooth extending from said pawl adapted to engage said ratchet wheel.

8. In a timing mechanism wherein cam means are rotated in response to motor drive means;

a. constant speed motor drive means,

b. cylindrical drive means coupled to and responsive to movement of said motor drive means, and gear means engaging said cylindrical drive means, said cylindrical drive means and said gear means constructed and arranged such that said gear means is alternatively held from rotation and advanced in response to rotation of said cylindrical drive means so as to intermittently advance said cam means,

c. second cam means responsive to said rotation of said cylindrical drive means including at least two tracks separated by peripheral ridges, and

d. sub-interval means responsive to movement of said second cam means in accordance with said rotation of said cylindrical drive means, said sub-interval means including at least two pivotally mounted levers, one each engaging one of said tracks.

9. In a timing mechanism wherein first and second 5 cam means are rotated in response to movement of motor drive means:

(a) constant speed motor drive means, (b) cylindrical drive means coupled to and respon- (c) second cam means responsive to said rotation of said cylindrical drive means. 

1. An intermittent drive means for driving a cam means comprising: a. a constant speed motor drive means, b. cylindrical drive means coupled to and responsive to movement of said motor drive means, said cylindrical drive means including a peripheral recess, and actuator means disposed on each side of said recess, c. gear means responsive to movement of said cylindrical drive means, said gear means including two sets of teeth, one of said sets having a thickness greater than the other, d. rotation of said cylindrical drive means causing engagement of said actuator means with said sets of teeth so as to rotate said gear means as the set of teeth of greater thickness rotates through said recess, further rotation of said cylindrical drive means engaging said set of teeth of greater thickness with the side of said cylindrical drive means so as to hold said gear means from rotation, e. means coupling said gear means to said cam means, including a ratchet wheel carried by a shaft, and a substantially semicircular pawl carried by a gear mounted on said shaft and a tooth extending from said semi-circular pawl.
 2. An intermittent drive means according to claim 1 wherein said actuator means includes a post disposed at each side of said recess.
 3. An intermittent drive means according to claim 1 further including sub-interval means responsive to rotation of said constant speed motor drive means.
 4. An intermittent drive means according to claim 3 wherein said sub-interval means includes: a cam means coupled to said constant speed motor drive means and at least one pivotally mounted lever means responsive to said cam means.
 5. An intermittent drive means according to claim 4 wherein said sub-interval cam means includes two peripheral tracks of coded indicia separated by a peripheral ridge.
 6. An intermittent drive means according to claim 5 wherein there are a pair of said pivotally mounted lever means.
 7. In an intermittent drive means wherein gear means and ratchet means are used to intermittently advance a cam means, the improvement comprising a ratchet wheel carried by a shaft; a semi-circular resilient pawl pivotally carried at one end by a gear mounted on said shaft, the other end engaging a post carried by said gear; and a tooth extending from said pawl adapted to engage said ratchet wheel.
 8. In a timing mechanism wherein cam means are rotated in response to motor drive means; a. constant speed motor drive means, b. cylindrical drive means coupled to and responsive to movement of said motor drive means, and gear means engaging said cylindrical drive means, said cylindrical drive means and said gear means constructed and arranged such that said gear means is alternatively held from rotation and advanced in response to rotation of said cylindrical drive means so as to intermittently advance said cam means, c. second cam means responsive to said rotation of said cylindrical drive means including at least two tracks separated by peripheral ridges, and d. sub-interval means responsive to movement of said second cam means in accordance with said rotation of said cylindrical drive means, said sub-interval means including at least two pivotally mounted levers, one each engaging one of said tracks.
 9. In a timing mechanism wherein first and second cam means are rotated in response to movement of motor drive means: a. constant speed motor drive means, b. cylindrical drive means coupled to and responsive to movement of said motor drive means, and gear means engaging said cylindrical drive means and coupled to sAid first cam means, said cylindrical drive means and said gear means constructed and arranged such that said gear means is alternatively held from rotation and advanced in response to rotation of said cylindrical drive means so as to intermittently advance said cam means, and c. second cam means responsive to said rotation of said cylindrical drive means. 